1. Field of the Invention
The present invention relates to a three-dimensional magnetic field sensor for detecting the three-dimensional direction of an external magnetic field, and to a method of producing the same.
2. Description of the Related Art
In recent years, three-dimensional magnetic field sensors for detecting the three-dimensional direction of an external magnetic field are used for the purpose of, for example, detecting the three-dimensional direction of terrestrial magnetism. Generally, a three-dimensional magnetic field sensor includes three detection elements for detecting the strengths of three mutually orthogonal components of an external magnetic field. A conventional three-dimensional magnetic field sensor has required that, for example, the arrangement of its three detection elements be specially designed because the sensitive directions of the three detection elements must be set to be orthogonal to each other. To configure three-dimensional magnetic field sensors, the following various technologies have been proposed.
In the technology disclosed in Japanese Patent No. 4293922, two magnetic sensor modules are side-mounted on a substrate, and one Hall element is bare-mounted on the substrate. One of the side-mounted magnetic sensor modules includes an internal Hall element that detects a terrestrial magnetism component in an X-axis direction parallel to the surface of the substrate, and the other side-mounted magnetic sensor module includes an internal Hall element that detects a terrestrial magnetism component in a Y-axis direction parallel to the surface of the substrate and orthogonal to the X-axis direction. The bare-mounted Hall element detects a terrestrial magnetism component in a Z-axis direction perpendicular to the surface of the substrate.
In the technology disclosed in JP-A-2007-256293, a V-shaped groove is formed in a substrate, and two magnetoresistive elements, one for detecting a magnetic field in an X-axis direction and the other for detecting a magnetic field in a Y-axis direction, are disposed on the surface of the substrate. In addition, another magnetoresistive element for detecting a magnetic field in a Z-axis direction is mounted on an inclined surface of the V-shaped groove.
In the technology disclosed in U.S. Pat. No. 6,545,462 B2, a magnetic field concentrator that alters the course of the lines of magnetic force is stacked on a semiconductor chip including a plurality of Hall elements, so that components of an external magnetic field in three directions can be detected.
In the technology disclosed in JP-A-2006-275764, a Hall element having a magnetic field sensitive axis in a Z-axis direction, a magnetoresistive element having a magnetic field sensitive axis in an X-axis direction, and a magnetoresistive element having a magnetic field sensitive axis in a Y-axis direction are disposed on a single substrate.
Three-dimensional magnetic field sensors can be configured with the technologies disclosed in Japanese Patent No. 4293922, JP-A-2007-256293, U.S. Pat. No. 6,545,462 B2, and JP-A-2006-275764 cited above. However, these technologies have the following problems.
The problem with the technology disclosed in Japanese Patent No. 4293922 is that, since the side-mounting of the two magnetic sensor modules on the substrate requires much time and effort, the production cost of the three-dimensional magnetic field sensor is high.
The problem with the technology disclosed in JP-A-2007-256293 is that, since the formation of the V-shaped groove in the substrate and the placement of the magnetoresistive element on the inclined surface of the V-shaped groove require much time and effort, the production cost of the three-dimensional magnetic field sensor is high.
The problem with the technology disclosed in U.S. Pat. No. 6,545,462 B2 is that, since there is a need for the step of stacking the magnetic field concentrator on the semiconductor chip including the plurality of Hall elements, the production cost of the three-dimensional magnetic field sensor is high.
The problem with the technology disclosed in JP-A-2006-275764 is that, since the step of forming the Hall element, which is a semiconductor element, is significantly different from the steps of forming the two magnetoresistive elements, the production cost of the three-dimensional magnetic field sensor is high.